title: A helix-turn-helix structure unit in human centromere protein B (CENP-B).
abstract: CENP-B has been suggested to organize arrays of centromere satellite DNA into a higher order structure which then directs centromere formation and kinetochore assembly in mammalian chromosomes. The N-terminal portion of CENP-B is a 15 kDa DNA binding domain (DBD) consisting of two repeating units, RP1 and RP2. The DBD specifically binds to the CENP-B box sequence (17 bp) in centromere DNA. We determined the solution structure of human CENP-B DBD RP1 by multi-dimensional 1H, 13C and 15N NMR methods. The CENP-B DBD RP1 structure consists of four helices and has a helix-turn-helix structure. The overall folding is similar to those of some other eukaryotic DBDs, although significant sequence homology with these proteins was not found. The DBD of yeast RAP1, a telomere binding protein, is most similar to CENP-B DBD RP1. We studied the interaction between CENP-B DBD RP1 and the CENP-B box by the use of NMR chemical shift perturbation. The results suggest that CENP-B DBD RP1 interacts with one of the essential regions of the CENP-B box DNA, mainly at the N-terminal basic region, the N-terminal portion of helix 2 and helix 3.
authors.affiliation: Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113.
authors.forename: J
authors.initials: J
authors.lastname: Iwahara
authors.forename: T
authors.initials: T
authors.lastname: Kigawa
authors.forename: K
authors.initials: K
authors.lastname: Kitagawa
authors.forename: H
authors.initials: H
authors.lastname: Masumoto
authors.forename: T
authors.initials: T
authors.lastname: Okazaki
authors.forename: S
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000595:Amino Acid Sequence; D001324:Autoantigens; D001482:Base Composition; D001665:Binding Sites; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry; D019077:Helix-Turn-Helix Motifs; D006801:Humans; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D012996:Solutions
chemical_list: D001324:Autoantigens; C497926:CENPB protein, human; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D012996:Solutions